


Guilt

by thewinchesterlifestyle



Category: Supernatural
Genre: Adopted Dean Winchester, Adoption, Adoptive Parent Castiel (Supernatural), Age Difference, Alpha Castiel, Alpha Michael, Alpha OMC, Alpha/Beta/Omega Dynamics, Alpha/Omega, Barebacking, Bottom Dean, Breeding, Daddy Issues, Daddy Kink, Fingering, Guilty Castiel, Knotting, M/M, Mildly Dubious Consent, Multi, Older Castiel, Omega Dean, Omega Samandriel, Possible Mpreg, Riding, Rough Sex, Rut, Size Difference, Size Kink, Teen Dean, Top Castiel, Underage - Freeform, Unsafe Sex, instincts, possible pregnancy
Language: English
Status: Completed
Published: 2018-03-01
Updated: 2018-03-01
Packaged: 2019-03-25 17:52:17
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,405
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13839936
Author URL: https://archiveofourown.org/users/thewinchesterlifestyle/pseuds/thewinchesterlifestyle
Summary: Castiel had never intended to adopt but Michael's worry over an Omega constantly passed up for younger kids had him acting. It was the least he could do. Castiel could give a teenager a home, something stable and safe, and ease some of Michael's worry at the same time.





	Guilt

**Author's Note:**

> Written for a prompt.

It had only been a few months since his brother, Michael, had called him up worrying about a newly fourteen year old Omega who had been in the system for years with nobody even glancing at him for adoption. Castiel had listened to Dean’s story and after seeing Dean, sad and resigned as another possible family passed him by, he had agreed to adopt him.

Castiel glanced into the kitchen and smiled at the sight of Dean sitting at the table, books spread out in front of him, as he worked on his homework. He could hear the faint scratch of Dean’s pencil on the page of his notebook and soft humming as Dean worked. “Don’t stay up too late.”

Dean jerked and turned to stare at him, green eyes surprised. “I’m almost done.” Castiel watched Dean glance away and reach for a bottle of water, uncapping it and chugging most of it. “Can I turn the air up?” there was a hopeful note in the tone that was impossible to miss.

“Sure.” Castiel watched Dean give him a grateful smile before the young Omega was up and walking out of the room. He walked over to the table and glanced over Dean’s work, nodding approvingly as he looked it over, before leaving the room and heading to his office.

He spent three hours going over paperwork, looking over proposals, until he called it a night. Castiel glanced in Dean’s room to see the teenager sleeping with covers twisted around his legs and a hand clutching his pillow. He pulled the door closed and moved down the hallway.

After finishing his nightly ritual Castiel climbed into bed and sighed as he relaxed against the cool sheets, eyes sliding closed. It was only moments later that he slipped into sleep.

It was mostly blackness until a dream started to take shape of a faceless Omega lying in his bed, whimpering and whining,  _begging_  for a knot with the sweetest smell. Castiel pressed closer to the dream Omega and moaned lowly in his throat as the scent seemed to get stronger.

“ _Cas._ ” The Omega sounded wrecked as Castiel nuzzled against the Omega’s neck, lazily rocking his hips up against him. “ _Cas?_   _Alpha?_ ”

There was something off about the way the Omega was talking but Castiel kept rocking forward against the Omega in his dream until something jarred him.

Castiel came awake with a jerk and a sharp inhale that he immediately regretted when it had him breathing in the heavy scent of Omega heatscent, slick and fertility. His cock was already hard and aching as his Alpha instincts screamed at him to claim or at the very least to _breed_.

He looked over to see Dean on his bed, completely naked with clothes discarded somewhere on the floor and whining lowly. The sweet scent of slick from a fertile Omega saturated the air in his room. “Alpha.” Dean moved closer and Castiel tried not to breathe. “I’m burnin’.” Dean released a broken sound.

Castiel knew from Dean’s file that the adoption agency his brother ran employed experienced Alphas and Omegas to help with Heats and Ruts when their charges needed. He knew that from Dean’s first Heat, at a surprisingly young age, up to his adoption Dean had spent every Heat underneath an Alpha, vigorously fucked and knotted, until his Heat ended.

But that was a service and Castiel was the one who adopted Dean. Legally he was listed as the teenage Omega’s adoptive _father_. Dean’s name had been changed to Dean Novak as the law had it where orphan Omegas automatically took their adoptive Alpha’s name.

“You need to leave.” Castiel gritted the words out as he shoved his instincts to the side. Dean was his adopted  _son_. He was responsible for the teenager and Dean should be far away from him.

He needed to call Michael and have Dean taken to the agency so one of the hired Alphas could help him. That would be the responsible thing to do until he could find an Alpha he could trust to take Dean through his Heats until he was mated.

According to Dean’s file he should have had a few weeks before Dean’s next Heat. It should have been weeks in which he would have had time to hire an Alpha or contact Michael and plenty of time for the injection Dean needed _before_ he went into Heat to prevent early pregnancy.

Somehow it had all gone to Hell and Castiel could tell that Dean was truly in Heat right now.

“Please.” Dean scooted closer and pressed into him, nuzzling and whimpering, as his fingers clutched at Castiel’s arm. “I need—”

“You need to leave. There are toys in your closet to help you with your Heat.” He clenched his eyes shut and tried to move away but Dean wasn’t leaving. “I’ll contact Michael and he’ll make sure one of their hired Alphas takes you through this.”

No matter what he said or how hard he tried to resist Dean was insistent. He pressed close and managed to get on top of Castiel to desperately grind down on Castiel’s sheet covered cock. Something in Castiel’s mind snapped and it was nothing but Alpha instinct driving him forward as the scent and feeling of a needy Omega triggered a Rut.

He wasted no time pushing Dean off so he could remove his pants, throwing them aside with a growl before focusing on the whining Omega who had shifted into a position to present. It wasn’t a surprise considering Dean hadn’t gone through a single Heat without an Alpha and there wasn’t a question that the ones Michael hired had taught Dean about proper presenting.

Castiel sank two fingers into Dean’s slick cunt, easily, as he pumped them a few times. He could feel how loose Dean already was as his Heat ready body loosened in preparation for breeding.

Dean kept shoving back into him and releasing desperate sounds. Castiel gritted his teeth at the feeling of Dean clenching around the three fingers he now had inside. It had been a few years since he’d fucked an Omega so much younger than him but his Rut clouded mind didn’t seem to care about Dean’s position as his adoptive son.

He pulled his fingers out and shifted up, guiding his thick cock inside and bottoming out in a smooth stroke that had Dean keening. It felt _amazing_ being completely buried inside a warm, slick Omega cunt as Dean’s inner muscles greedily squeezed him. He ignored Dean's age and focused on pleasure.

Castiel’s fingers dug into the flesh of Dean’s hips as a snarl rumbled in his chest. He started up a quick, harsh rhythm that had him groaning in bliss and the headboard knocked against the wall. It had been two weeks since he’d had sex and the constant exposure to a young, ripe Omega had finally caught up to him. He should have never cut back but he’d worried about constantly smelling of other Omegas around his new son.

Dean gasped something that Castiel didn’t quite catch until it came again.

“ _Daddy_.”

Castiel’s eyes slipped closed and he groaned low in his throat. Something about that one word went straight through him and his motions faltered. It shouldn’t have had heat surging inside of him, it was dirty-bad- _wrong_ , but arousal burst inside of him at the young voice sounding so wrecked and calling him _that_.

“Daddy  _please_.” Castiel snarled and started slamming inside Dean’s cunt even harder, chasing his knot as it built up at the base of his cock. He could practically taste his orgasm and Dean’s broken, rough chants of  _Daddy please harder harder_  had him slamming inside with a vicious sound as his knot swelled and caught in Dean’s cunt.

Castiel barely restrained himself from biting the back of Dean’s bared neck when the young Omega’s cunt clamped down around him, milking his knot hungrily, even as Dean’s own orgasm overcame him and flooded his passage with even more slick. There was something like a wail that escaped Dean as Castiel ground himself against Dean’s cunt. His face was pressed against Dean and he was draped over the young Omega, pressing him into the mattress, as his cock spilled load after load inside a fertile cunt.

“Thank you.” Dean’s fingers had relaxed their grip on the sheets and Castiel could feel how lax Dean was under him. “Felt too hot.” His tone was dazed and sated. The tone of a well fucked in-Heat Omega.

The relief and clarity he’d received from his Rut had guilt flooding Castiel. If he’d acted sooner he could have avoided this. Now his knot was getting milked by Dean’s cunt, he was in a Rut and the likelihood of Dean being bred was very high.

“I’m sorry.” Castiel hated himself for giving in. Now that he had tied Dean the instincts that had urged him on were sated. His Rut would slowly start back up an hour or so after his knot shrunk and Dean, in Heat and saturated in Castiel’s scent, would call to his instincts like a siren. It would take a few more hours before his Rut took over and his restraint disappeared. “I’m responsible for you and I let myself lose control.” He closed his eyes and tried to imagine he wasn’t knotted to an underage Omega he’d  _adopted_ to give a good home.

He was ashamed. It was one thing to fuck, knot and possibly breed an underage Omega but one that was legally his son was a completely different matter.

“Not your fault.” Dean reached back and grasped his wrist, squeezed briefly, before sighing when Castiel felt his cock spill more of his release inside Dean’s cunt. “The Heat isn’t so bad now.” There was relief in the tone but Castiel still felt something twisting in his stomach. “None of the other Alphas who used me during my Heat apologized.” He waved Castiel’s guilt away, “Need to be full during my Heat.”

“You’re spending the rest of your Heat in a room at the agency with a hired Alpha who _didn’t adopt you_.” He kept his voice firm and didn’t notice the look on Dean’s face. It was a look that said Dean was going to do anything but spend his Heat away.

Hours later, when Dean’s Heat had driven him past reason once more, Castiel woke from an uneasy sleep to the Omega once more in his bed only this time Dean was riding him. The young Omega’s breathing coming in hitches and gasps as he fucked himself down on Castiel’s cock with more whimpers of  _Daddy I’m empty_  and  _Daddy please…I need your knot_  that had Castiel thrusting up with a growl.

He took Dean two more times, Rut snarling inside of him, as Dean begged and sobbed for more until he managed to contact Michael.

Dean fought against him in the shower as Castiel forced himself to focus, cleaning Dean up and rinsing his cunt, before he shoved Dean into lounge pants and a hoodie in time to haul him down the stairs.

Michael stepped inside, took one look at him and sighed. He stepped forward with the mild sedative and within seconds Dean had gone limp in Castiel’s hold. Omega gold eyes, hooded and dazed, blinked lazily at him as Dean relaxed against him with a sigh.

“That should help keep him calm and hold back some of the desperation until we get him back to the agency. I’ve already got an Alpha in a room for him. How long has he been in Heat?”

“Four or so hours.” Castiel gritted out as he carried Dean towards Michael’s car. Dean was mumbling, asking for an Alpha, as Castiel put him in the back. “He’s weeks early.”

“Something must have triggered it.” Michael looked at him with pity, “Set your Rut off, didn’t it?” he paused, “Get in. I have several Omegas at the agency and one of them can take you through your Rut. They’re all on birth control so you have nothing to worry about.” The second he agreed Michael made a call to have a room and Omega ready for him.

It was a relief when the car pulled up to the agency, Dean stumbling along under Michael’s arm and guided into a Heat room where a stereotypical bulky Alpha who looked older than Castiel waited already naked. Castiel watched next to Michael as the Alpha stripped Dean’s clothes methodically, tossed them aside and pushed Dean into a mountable position on the inclined breeding stand in the room.

Dean’s cunt was red, swollen and soaked as the Alpha fucked himself right inside with a loud, indulgent groan of pleasure. Laid out under him Dean moaned, whined and gasped with each powerful snap of the Alpha’s hips as he hammered into Dean with equally pleasured sounds.

“Come on, Cas.” Michael tugged him back.

The Heat room was locked, Castiel knew they were monitored and the rooms well supplied, as Michael guided him out of the Omega area. He could feel his Rut snarling inside of him, his cock straining painfully against his pants, as Michael spoke to staff and guided him into a room that had been prepared at Michael’s request.

Castiel stepped inside to the scent of Omega and slick. There, already draped over a breeding stand instead of laid out on the bed, was a young Omega. The cunt was slick, swollen with arousal and empty.

“That’s Samandriel. He’s eighteen and one of the best Omegas I hire to help out at the agency.” Michael pushed him into the room. “If you need anything that isn’t in the room push the button on the wall and someone will get it for you.”

The door shut behind him and Castiel wasted no time in stripping, stepping up to the pliant Omega and guiding himself inside. This time there was no guilt, nothing churning his stomach, as he sheathed himself inside an Omega cunt.

Instinct took over, his Rut slamming into him, as Castiel started to vigorously pound into the Omega under him. Breathy moans and gasps of _Alpha_ filled the room urging him on as he fucked roughly into Samandriel.

Without the need to worry about Dean and knowing Michael would take care of any calls Castiel gave himself over to his Rut without a fight.

**Author's Note:**

> Wasn't this a bit of a tangled up mess? Poor Cas trying to do the right thing, give a young Omega a home and father figure, only to lose himself to instinct when Dean goes into Heat and triggers his Rut. I tagged this as "possible pregnancy" since the last the reader sees of Dean in this is at the beginning of his Heat and an Alpha is, basically, getting paid to unknowingly breed Dean (because Cas didn't think to tell Michael that Dean hadn't gotten his shot). Ooops!
> 
> I don't think I've posted anything on here like this before so hopefully this different kind of fic was a good read! Or at least a nice break from some of my typical fics.
> 
> I'm looking forward to hearing what you thought of it!
> 
>  
> 
> \--Yes I'm using this next bit on each of the new fics I post from my folder since it fits all of them (yay copy and paste).--
> 
> Again I'm still going through that folder on my laptop though I keep getting a bit distracted so this is getting dragged out a bit. This fic is another one that was waiting to be finished, fixed and posted.
> 
> Leave a comment and let me know what you thought. Your comments and thoughts are always appreciated!


End file.
